Name a character and I'll tell you three (or more) facts about them from my own personal headcanon.

CANONS:

Yugioh (Any)
Pokemon (Anime, Special, Games)
Digimon (Any)
Discworld (First two Rincewind books, first 4 Watch Books, First 3 Death Books, Small Gods, Moving Pictures)
Harry Potter
A Series of Unfortunate Events
Avatar, The Last Airbender
Heroes
Bleach
Naruto(Manga)
Good Omens
V for Vendetta (Film)
The League of Extraordinary Gentlemen (Comic and Film)
Sandman (First 3 Volumes/Contents of Absolute Sandman)
Sailormoon
Mai-Hime/Otome
Hitchhiker's Guide to the Galaxy (Book Series + Film)
Dirk Gentley
Final Fantasy (7, 9, 10, 10-2)
KINGDOM HEARRTTTTS
Tokyo Mew Mew
Deathnote
Gundam Seed
Code Geass Lelouch of the Rebellion
Golden Sun
Eureka Seven
Errant Story
A Miracle of Science
Girl Genius
Gunnerkrigg Court
Dresden Codak
Elf Only Inn
Darken
Way too many more webcomics
Any RP Character I've played/played with
Enigma Characters (Not that anyone besides Neo+Misa should know any)
Other Original Characters (Except the ones that don't exist)